Abstract: In order to investigate the penetration resistance of steel fiber reinforced concrete (SFRC), 12.7 mm armor-piercing projectiles and long rod projectiles are used to penetrate a high strength fiber reinforced concrete backed by armor steel in high speed impact test. The penetration resistance of composite target is evaluated using protection factor according to the penetration depth of rear target. The lattice discrete particle model (LDPM) is introduced to model fiber reinforced concrete, and the elastic-plastic model and Johnson-Cook criterion are used to describe the projectile and armor steel. A numerical simulation model for penetration into concrete target is established. The feasibility of numerical model for simulation of penetration into fiber reinforced concrete is validated in terms of penetration depth and concrete target damage mode. The effects of internal gap and fiber content of composite target on penetration response in 3 typical penetration tests are simulated and analyzed. The numerical results show that, for the composite target without gap, the residual penetration depth of rear target can be effectively reduced, and the fiber reinforcement has no effect on the penetration depth but affects the concrete damage mode significantly. Further numerical analyses of fiber reinforced concrete target perforated by 12.7 mm armor-piercing projectiles indicate that the perforation velocity of projectile tends to converge if the diameter of cylindrical target is 30 times larger than projectile diameter, and the residual velocity approximates a linear relationship with impact velocity with the decrease in target thickness. Key

Key words: ordnancescienceandtechnology, fiberreinforcedconcrete, penetrationresistance, numericalmodeling, perforationresponse